The invention relates to a filter cartridge unit comprising a first end plate, at least one second end plate, and a filter cartridge which is arranged between the end plates.
Filter cartridge units are used, for example, in the ultrafiltration and microfiltration of liquids. Filter cartridges or membrane cartridges are usually positioned adjacent to a distribution plate and are clamped and pressed together with the aid of a filter holder between two clamping plates or end plates. The distribution plate has connectors for the medium to be filtered and connectors for the filtrate or permeate and, in the case of cross-flow filtration, connectors for the retentate or concentrate. In order to connect to the filter cartridges which are engagable or stackable one after another, the distribution plate has channels in the interior thereof which are connected to the connectors.
Filter cartridge units of this type are known, for example, from DE 34 41 249 C2, DE 44 32 627 A1 or DE 100 00 186 C2.
A disadvantage of the known filter units that have become well established is that, following use, the filter cartridge unit has to be disassembled and the filter cartridge must be removed. This can result in undesirable contamination of the end plates, the distribution plates or other parts of the surroundings.
A further disadvantage of the known filter units configured as multi-use devices is that complex cleaning and validation steps are needed to preclude cross-contamination if the user filters different media successively with one filter unit.
U.S. Pat. No. 5,429,742 discloses generally that filter cartridges can be glued to the end plates. However, U.S. Pat. No. 5,429,742 does not disclose more detail concerning the glued connection.
It is known from DE 68 01 138 U to stack filters or membranes and to hold the stack together with end plates. For this purpose, the membranes, the plates arranged between the membranes and the end plates have holes which form channels due to the stacking and which can be filled with a curable plastics adhesive.
U.S. Pat. No. 4,882,050 discloses filter plates which are also layered on one another and are clamped together via end plates. It is known, for correctly placed assembly, either to mold projecting elements, which engage in corresponding recesses of the filter plates, onto the end plates or to fasten these projections on by gluing.
In addition, DE 31 27 548 C2 discloses a filter cartridge unit wherein support plates and membrane filters stacked over one another have perforations in the stacking direction that can be filled with adhesive or synthetic resin. The end plates are clamped to one another by means of clamping elements guided by bolt bores.
U.S. Pat. No. 4,849,102 describes a filter cartridge unit with a distribution plate arranged between two filter cartridges, wherein the filter cartridges are clamped between two end plates.